Dogs perceive pheromones with their vomero-nasal organ (VNO). This paired organ, situated above the hard palate, opens into the incisive canal, which connects the mouth cavity with the nasal fossae.

Section of vomero-nasal organ.









The glands seem to be involved in the secretion of different proteins found in the vomero-nasal mucus. Among these proteins are Pheromone Binding Proteins (P.B.P.) which carry pheromones towards the receptors.

When a dog comes into contact with secreted pheromones, lapping and panting behaviours are observed, similar to the flehmen reaction seen in other species, for example the cat.

Detection of "appeasing" pheromones Stimulation of the specific receptors leads to depolarisation of the vomero-nasal nerve which connects the VNO with the accessory olfactory bulb. Subsequently, different connections stimulate different structures within the limbic system, thus altering the emotional state of the dog.